Red Arrow's costume in young justice league he has a red collared shirt that goes down into a v then turns black anyone have any ideas where i could get a shirt like this or how i would make one? Any help would be appreciated.

I'm currently working on a YJ Red Arrow costume myself. For the shirt, I took a black tank top that I had and I took a red turtleneck(which I found for $1 at Wal-Mart), and I cut them so that I had a diamond shape and collar for the red shirt, and that same shape was also cut out of the black tank top so that they fit together. I then took some black thread and sewed them. From the black fabric I had cut out of the tank top, I cut out a long thin strand to put down the front, like he has on the show. I'm not sure if this is the most accurate material-wise but it's fairly cost-efficient and it doesn't take too long to do.

Another suggestion would be to get a black body suit and cut the sleeves off, then put some red fabric on that. Hope this helps some!(even though its been a year and three months since you posted that...)